Scrubbing fluid coking effluent

Claim 1

IN A FLUID COKING PROCESS WHEREIN A CHARGE OF HIGHBOILING CONSTITUENTS IS COKED AND THE EFFLUENT IS SCRUBBED TO SEPARATE OUT A GAS-OIL STREAM NORMALLY CONTAINING OBJECTIONABLE AMOUNTS OF RESIDUUM, AND A HEAVY STREAM, NORMALLY RECYCLED, THE IMPROVEMENT COMPRISING INTRODUCING THE EFFLUENT INTO THE LOWER END OF A SCRUBBING ZONE HAVING A TEMPERATURE GRADIENT LYING BETWEEN TEMPERATURES LOW ENOUGH TO SUBSTANTIALLY FREE SAID GAS-OIL STREAM FROM RESIDUUM, SAID GAS-OIL STREAM LEAVING FROM ABOVE SAID ZONE, AND TO DRIVE SOME GAS-OIL AND SUBSTANTIALLY ALL OF SAID RESIDUUM DOWN INTO SAID HEAVY STREAM, WHICH LEAVES FROM BELOW SAID ZONE; DISTILLING SAID HEAVY STREAM IN A DISTILLATION ZONE AT SUBSTANTIALLY ITS WITHDRAWN TEMPERATURE BY MEANS OF ITS HEAT CONTENT WHEN WITHDRAWN AND AT A PRESSURE BELOW 50MM. HG WHILE SIMULTANEOUSLY INTRODUCING STREAM IN A QUANTITY SUFFICIENT TO FURTHER REDUCE THE HYDROCARBON PARTIAL PRESSURE AND LOWER THE TEMPERATURE GRADIENT IN THE DISTILLATION ZONE, THUS MAKING ADDITIONAL SENSIBLE HEAT AVAILABLE, USING SAID ADDITIONAL HEAT TO EFFECT AN ADEQUATE REFLUX OF OVERHEAD DISTILLATE, THEREBY OBTAINING A SUBSTANTIALLY RESIDUUM FREE GAS-OIL STREAM AS OVERHEAD PRODUCT AND A BOTTOMS STREAM CONTAINING A MINIMUM OF GAS-OIL; AND CHARGING SAID BOTTOMS STREAM BACK AS PART OF SAID COKING CHARGE.